Interface structure and properties of spray-forming (SiCp plus β-LiAlSiO4)/6092Al matrix composites

45 wt.% SiCp/6092Al, 5 wt.% beta-LiAlSiO4/6092Al and (45 wt.% SiCp + 5 wt.% beta-LiAlSiO4 (Euc))/6092Al matrix composites were successfully fabricated by spray-forming and die forging technology. The microstructures, interface structures, and phase composition of the composites were analyzed with optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffractometer (XRD). The thermal expansion properties, bending strength, and bending modulus of the composites were tested by thermal dilatometer and electro-mechanical universal testing machines, respectively. The results show that the SiCp and beta-LiAlSiO4 (Euc) particles are uniformly distributed in the 6092Al matrix, and a strong bonding interface is formed with the Al matrix. The SiCp/Al, and Euc/Al interfaces of the (45 wt.% SiCp+5 wt.% Euc)/6092Al matrix composite are straight and clear. However, the interface reaction is not found. After solution treatment and artificial aging (T6), the coefficient of thermal expansion (CTE), bending strength, and bending modulus for (45 wt.% SiCp + 5 wt.% Euc)/6092Al matrix composites are 14.68x10-6 K-1 in the temperature range of 303-473 K, 589 MPa, and 165 GPa, respectively. Key words: spray-forming; Al matrix composites; interface structure; coefficient of thermal expansion (CTE); bending strength; bending modulus

Automated summary

45 wt.% SiCp/6092Al, 5 wt.% beta-LiAlSiO4/6092Al and (45 wt.% SiCp + 5 wt.% beta-LiAlSiO4 (Euc))/6092Al matrix composites were successfully fabricated using spray-forming and die forging technology. The microstructures, interface structures, and phase composition of the composites were analyzed using various techniques. The thermal expansion properties, bending strength, and bending modulus of the composites were tested. The results showed uniform distribution of SiCp and beta-LiAlSiO4 (Euc) particles in the Al matrix, with strong bonding interfaces. The (45 wt.% SiCp + 5 wt.% Euc)/6092Al matrix composite had clear and straight interfaces. After T6 treatment, the composite exhibited specific thermal expansion, bending strength, and bending modulus values.